Pulmonary fibrosis Flashcards
What is interstitial lung disease?
Wide range of diseases
At the most extreme end culminate in pulmonary fibrosis
7% of lung diseases culminate in ILD
Where does gas exchange take place in the lung?
Across fused basement membrane of the endothelial and epithelial cells
What is the space between the endothelial and epithelial basement membrane called?
Interstitial space
What is the histology of a normal intestitial space?
Narrow bridge of lung tissue
Populated by occasional fibroblast
What happens to the structure of the lung during ILD?
Increase in size of the interstitial space
Gas exchange is compromised
Fibroblastic foci around the alveolar capillary approach alveolar space
What does the lung look like in late stages of ILD?
Lung becomes scarred, fibrotic and difficult to see original structure
What is the lung’s response to injury?
Limited response
Hard to predict - depends on genetic background
Why is the lung easily injured?
Very exposed to toxins in the blood and allergens
What can be used to observe the response of lungs to injury?
CT scan
What are the 3 ways in which the lung can respond to injury?
Response can be:
Inflammatory - immune systen
Fibrotic scarring - fibroblast proliferation and ECM production
Or both
What is the role of T cells and macrophages in ILD?
Th2 produce IL 13 which works with TGF b to differentiate and proliferate the fibroblasts -> myofibroblasts
What induces the differentiation of fibroblasts -> myofibroblasts?
TGF b
IL 13
How do you diagnose pulmonary fibrosis?
Blood test and in-depth history to conclude source
Full history - jobs done and houses lived in
What are the 3 types of ILD?
Organising pneumonia
Interstitial pneumonia
Non-specific interstitial pneumonia
Characteristics of organising pneumonia
Whirls of not well organised fibroblasts
Not much ECM has been laid down
Patient will be left with some fibrosis
